Figure 5.

¹³C NMR kinetic measurements of glucose utilization (A) and lactate formation (B). Controls — cells were perfused with [¹³C₁]-glucose-enriched medium and ¹³C spectra were continuously recorded. HGF/SF — following a complete washout for 60 minutes with normal medium, the cells were perfused with DMEM containing 100 ng/ml HGF/SF for 60 minutes and the ¹³C NMR experiment was repeated. Phloretin — following a second complete washout with normal medium, the cells were perfused with DMEM containing phloretin (200 mM) and the ¹³C NMR spectra were recorded again on the same sample. The time scale starts at the point at which [¹³C₁]-glucose reached the cells. Results of one out of three different experiments are shown. Metabolite levels were determined by normalizing NMR signals integrals to the reference (dioxane in a capillary), and to the protein content of the cell.